multiplication

$\dfrac{a}{b}\times c = \dfrac{a\times c }{b}$.

Examples: 

$\dfrac{5}{7} \times 2 = \dfrac{5\times 2}{7}= \dfrac{10}{7}=1\dfrac{3}{7}$

$\dfrac{2}{3}\times 15 = \dfrac{30}{3}=10$

$\dfrac{4}{9}\times 32 = \dfrac{128}{9} = 14\dfrac{2}{9}$